Railway-traffic-controlling apparatus



July 23, 1929. L. v. LEWIS RAILWAY TRAFFIC CONTROLLNG APPARA'T-'S Filed sept; 29., 1928 INVENTOR Nw mw KN @N Patented July 23, 1929.

UNITED .Y STATES 1,721,961 PATENT oFFlcE.

LLOYD V. LEWIS, OF EDGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY-TRAFFIC-CONTROLLING APPARATUS.

Application filed September 29, 1928. Serial No. 309,215.

My invention relates to railway trafiie controlling apparatus, and particularly totraincarried apparatus of the type wherein the brakes of the train are controlled jointly by traffic conditions in advance and the speed of the train.

I will describe one form of train carried apparatus embodying my invention, andy will then point out t-he novel features thereof 1n claims.

The accompanying drawing is a view, partly diagrammatic and partly in section, showing one form of apparatus embodying my invention.

Referring to theV drawing, the reference character R designates a train control relay which, as here shown, is of the induction motor type comprising two stator windings 1 and 2 and a` rotor 3. The rotor operates contact fingers 4 and 5. This relay is controlled by tratlic conditions in advance of the train in such manner that when traffic conditions are clear, so that high speed is permissible, the contact fingers 4 and 5 are swung to the right; under caution trallic conditions, that is, conditions requiring a medium speed limit, the contact fingers are swung to the left; and under danger traflic conditions, that is, conditions requiring a low speed limit, the contact fingers occupy their intermediate or vertical positions. The apparatus for controlling the relay R forms no part of my present invention and is therefore omitted from thc drawing.

The train is provided with a speed limit indicator or cab signal S, 'comprising three lamps SH, SM and SL, which lamps -when lighty ed indicate high speed, medium speed and low speed, respectively. The circuit for the high speed lamp SH is from terminal 'B of a suitable source of current, through contact 4 4n of relay R, wires 6 and 6a, and lamps SH to terminal O of the same source of current. The circuit for lamp SM is similar to the circuit ust traced, except that it includes contact 4*4h of relay R and wires 11 and 12.

The circuit for lamp SL is from terminal B,

through contact 5 5a of relay R, wires 14, 15 and 16, and lamp SL to terminal O. It will be seen, therefore, that lamp SH is lighted when the relay R is energize-d in the high speed direc-tion, lamp SM is lighted when the relay is energized in the medium speed direction, and the lamp SL is lighted when the relay is deenergized. Y

The train lcontrol relay R also controls speed 'governing mechanism comprising a 'highspeed magnet H, a medium speed magnet M, and a low speed magnet L.v These magnets, together with a centrifugal device C, `control. a pneumatic relay comprising a pair of contacts 25 and 26, which contacts in turn control a valve magnet A, and the valve magnet A automatically controls the air brake apparatus on the train.

The high speed magnet H operates a high speed, pilot valve BH, the medium Ispeed magnet M operates a medium speed pilot valve BM, and the low speed magnet L operates a low speed pilot valve BL. The speed governing mechanism also comprises a normally closed high speed valve VM, a. normally closed medium speed valve VM, and a normally closed low speed valve VL. Each valve Vis biased to t-he closed position' by a spring 42. These valves are controlled by tappets f41 mounted in a crosshead 40 which is operated by the centrifugal device C. The centrifugal device isoperatively connected with an aXle of the train through the-mediurnof bevelled lgears 38 and 39, as well as otherv mechanical driving mechanism not shown inthe drawing. The valves V'are operated in such mannerthat when the train exceedsr a given low speed limit valve VL is opened, when the train exceeds a given medium speed limit v the valve VM 1s opened, and when a tram.

exceeds a given highspeed limit the valve VH is` opened. l

The brake controlling contacts 25 and 26 are operated by a piston 44 responsive to variations of fluid pressure in a cylinder 43 which is always connected by pipe 45 with the high speed valve VH. When the high speed magnet His energized, cylinder 43 is connected with a p ipe P through a restricted orifice the pipe P. is connected with Aa source of fluid pressure which isnot shown in the drawing. lVhen the high speed magnet. H is cle-energized and the medium speed' magnet. M is energized, the cylinder 43 is connected with pipe P, and also with the medium speed valve VM through a pipe 46. Vhen magnets H and M are de-energized and the low speed magnet L is also deenergized, the cylinder 43 .is connected with atplication, a pick-up circuit for magnet L will be closed, which circuit passes from terminal B, through contact 5--5a of relay R, wires 14, and 19, contact 2O of acknowledging switch E, contact 21 ofV pneumatic relay D, wire 22, and the winding of magnet L to terminal O. When magnet L becomes energized, it will close a contact 24 which is operated by the armature of this magnet, and a stick circuit for magnet L will then become closed. This stick circuit is from terminal B, through contact 5--5a of relay R, wires 14 and 23, contact 24, and winding of magnet L to terminal O. Magnet L will then remain energized as long as dangerous traffic conditions exist, thatis, asv long as relay R remains de-energized. Pilot valve BL will now be depressed, thereby connecting cylinder 43 with the supply pipe P and also with the low speed valve VL through pipe 47. If the train exceeds a. given low speed, valve VL will be opened to reduce the pressure in cylinder 43 and so to cause an automatic application of the brakes after they expiration of a'short interval of time.

It will be noted that when the engineer reverses the acknowledging switch E, contact 28 will become open, thus requiring that this switch be restored to its normal position at once in order to avoid an automatic application due to de-energiZation of magnet A. It will also be noted that the acknowledgment must occur before an automatic brake application is initiated, becauseotherwise contact 21 will be open and will prevent the closing of the pick-up circuit for the low speed magnet L.

The purpose of the restricted orifice 51 is to prevent unnecessary blowing of whistle 37 while the train is passing over block joints and other locations where the control of relay R is unavoidably interrupted for short intervals of time.

The purpose of the restricted orifice in the supply pipe P is to cause a large variation in the pressure in cylinder 43 as the result of a small movement of each valve V. I will assume that the pneumatic relay F is so adjusted that its contacts will open when the pressure in the cylinder 43 is reduced to onehalf of its normal value. This will occur Whenthe effective area of the exhaust through each valve V is approximately the same as the cross-section of the restricted orifice 50. Assuming that the orifice 5() is g in diameter, and that the effective diameter of each valve V is 'rg, this valve need be opened only .003v in order to make its effective area equal to the area of the' restricted orifice, and, of course, only an extremely small movement of the crosshead 40 is necessary to produce this amount of opening of the valve. In other words, an extremely' small movement of a valve V will cause a large fluctuation in the pressure in cylinder 43. For this reason, the differential pressure required to operate the pneumatic relay F from the closed to the open position'or vice-versa, is accomplished with an extremely smalll change in speed, so that the speed limiting mechanism "f is extremely sensitive. In practice, the contacts 25 'or 26 off-relay F are preferably constructed in the form of the `usual toggle lor snap switch mechanism, so that their Voperation is quick and positive even though the pressure in cylinder 43 is changing slowly, thereby to avoid burning or arcing of the contacts at critical speeds. 1

One advantage of apparatus embodying my invention, isV that the selection of speed limits and the brake application mechanism are accomplished electrically, thereby avoiding the complications inherent inthe large number of valves and pipes which would be required if these functions were performed pneumatically. At'theV same time, I have retained the advantages of the pneumatic speed governor which is considerably more sensitive, reliable and accuratethan any governor in which contacts are actuated mechanically by centrifugal force. The reason for this is that electrical contacts, to be operated i reliably, require more stroke and pressure than can be developed mechanically as the result of a small change in the position of the weights of the centrifugal device due to a small increase or decrease in speed.

Although I have herein shown and described only one form of apparatus embody-k ing my invention,it isunderstood that various changes and modifications may be made therein within Athe scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is 1. Train control apparatus comprising a cylinder connected with a-sourceof fluid pressure through a restricted orifice, a normally closed valve connected with said cylinder, a centrifugal device operatively connected with a wheel of the'train, means operated byisaid centrifugal device for opening said valve when the speed of the train exceeds a given value, a movable member responsive to variationsof the pressure in said cylinder, a contact'operated by said member, and train governing mechanism controlled by said contact. f 2. Train control apparatus comprising a cylinder, a movable member associated with said cylinder and responsive to variations of pressure therein, a contact-operated by said member, train governing mechanism controlled by said contact, a plurality of valves, means for selectively connecting said cylinder with said valves, and means foropening said valves at different speeds of the train.

3. Train control apparatus comprising a cylinder, a movable member `associated with iao said cylinder and responsive to variations of pressuretherein, a-contactoperated by said vmember, train governing mechanism controlled by-said contact, a plurality of valves, means for `s electively connecting said cylinder with said valves, a centrifugal device operatively connected Witha wheel of the train, and means operated by said device for progressively opening said valves as the speed ofI the train increases.

"1l, Traincontrol apparatus comprising a cylinder connected with a source of fluid pressure through a restricted orifice, a normally closed valve connected with said cylinder, means for opening said valve when the speed of the train is above a given value, a movable member responsive to variations of the pressure in said cylinder, a contact operated by said member, and train governing mechanism controlledby said contact.

5. Train control apparatus comprising a cylinder, a movable member associated .with saidcylinder and responsive to variations of pressure therein,.a contact operated by said member, train governing mechanism controlled by lsaid Contact; means for supplying' fluid pressure to said. cylinder through a restricted orifice, a plurality of valves, means for selectively connecting said cylinder With said valves, and means for opening said valves at different speeds of the train.

6. Train control apparatus comprising a Y cylinder, a movable member associated with said cylinder and responsive to variations of pressure therein, a` contact operated by said member, train governing mechanism controlled by said contact; means for-supplying fluid pressure to said cylinder through a restricted orifice, a pluralityof normally closed valves, means for selectively'` connecting said cylinder with said valves, a centrifugal deviceoperatively connected with a Wheel of the train, and means operated by said device for progressively opening said valves as the speed of the train increases.

7'. Train control apparatus comprising a cylinder, a. movable member associated with said cylinder and responsive to variations of pressure therein, a contact operated by said member, train governingy mechanism controlled by said contact; a high speed valve constantly connected Avvith said cylinder, a medium speed; valve, a1loW speed valve, all of which valves are biased to the closedposition, ahigh-speed magnet, a medium speed magnet and a lo7 speed magnet, means operating Whensaid high speed magnet is energized to connect said cylinder yWith a source of fluid pressure through arestricted orifice, means operating when said medium speed magnet is energized and said high speed magnet is de-energized to connect said cylinder With said medium speed valve and With said source of fluid pressure and restricted orifice, means operating when said low speed'magnet is energized and said high speed and medium speed magnets arek de-energized to connect said cylinder With said loW speed valve aswell as With said source of pressure and restricted orifice7 means 'operating when .all of said magnets are cle-energized to connect said cylinder with atmosphere but not With said source of pressure;v and means for opening said low speed valve when the speed of the train exceeds a given low value, lsaid medium speed valve when the speed exceeds a; given medium value, and said high speed valve when the speed exceeds a given-high value.

S. Train control apparatus comprising a cylinder, a movable member4v associated with said cylinder and responsive to variations of pressure therein, a' contact operated by; said member, train governing mechanism con-l trolled by said Contact;l ahigh speed, valve constantly connectedwvith said cylinder, a me,-` dium speed valve, a low speed valve, all of which valves are biased to the `closed position, a high speedmagnet, a medium speed magnet and a low speed magnet, a high speed pilot valve controlled by said high speed magnet and operating When the magnetis energized to connect said cylinder With a2 source of fluid pressure through a restricted orifice,

a medium speed pilot valve controlled by said v medium speed magnet and operating When the magnet is energized and saidv highy speed magnet is cle-energized to connect saidcylinder With said mediumspeed valve and with said source of fluidpressure and restricted orifice, a low speed pilot valve -controlledby said low speed magnetandy operating When the magnet is energized and the other tWo magnets are de-energized to connect said "cylinder with said low speed valve as Well as Withsaid fluid pressure source and-restricted orifice, said pilot valvesoperating when. all-three magnets are de-energized to connectsaid cylinder with atmosphere but not with said source of pressure,vand means.k for .opening said low speed valve When the'sp'e'ed of the train exceeds a given low value, said-medium speed valve when the speed exceeds a--given medium value, and saidhigh speed-valvel when the speed exceeds a given high value. f

9. Train control apparatuscomprisinga cylinder, a movable member associated with said cylinder andl responsive tovariations of pressure therein, a contactV operated by said member, train governing mechanism controlled by said contact; a high speed valve constantly connected With said` cylinder, a medium speed valve, a low speed valve, all of which valves are biasedftothe closed position, a high speed magnet, al medium speed magnet and a low speed magnet, means operating when said high speed magnet is energized to connect said cylinder with a source of Huid pressure through a restricted orifice, means operating When said medium speed. magnet is energized and said high image1 speed magnet is deenergized to connect said cylinder when said medium speed valve and with said source of fluid pressure and restricted orifice, means operating when said low speed Vmagnet is energized and said high speed and medium speed magnets are de# energized to connect said cylinder with said low speed valve as Well as with said source of pressure and restricted orifice, means operating when all of said magnets are de.- energized to connect said cylinder with atmosphere but not with said source of pres.- sure; a centrifugal device operatively connected with an axle of the train, and means operated by said device for opening said low speed valve when the speed of the train exceeds a given loW value, said medium speed valve when the speed exceeds a given medium value, and said high speed valve when the speed exceeds a given high value.

10. Train control apparatus comprising a cylinder, a movable member associated with said cylinder and responsive to variations of pressure therein, a contact operated by said member, train governing mechanism controlled by said Contact; a high speed valve constantly connected with said cylinder, a medium speed valve, a lo-W speed valve` all of which valves are biased to the closed position, a high speed magnet, a medium speed magnet and a low speed magnet, a high speed pilot valve controlled by said high speed magnet and operating When the magnet is energized to connect said cylinder with a source of'fluid pressure through a restricted orifice, a medium speed pilot valve controlled by said medium speed magnet and operating when the magnet is energized and said high speed magnet is de-energized to connect said cylinder with said medium speed valve and With said source of fluid pressure and restricted orifice, a low speed pilot valve lcontrolled by said loW speed magnet and operating When the magnet is energized and the'other two magnets are de-energized to connect said cylinder With said loiv speed valve as Well as with said fluid pressure source and restricted orifice, said pilot valves operating when all three magnets are cle-energized to connect said cylinder With atmosphere but not With vsaid source of pressure, a Vcentrifugal device operatively connected With an axle of' the train, and means operated by said device for opening said loW speed valve When the speed of the train exceeds a given loW value, said medium speed valve When the speed exceeds a given medium value, and said high speed valve when the speed exceeds a given high value.

11. Train control apparatus comprising a cylinder, a movable member associated with said cylinder and responsive to variations of pressure therein, a contact operated by said member, train governing mechanism controlled by' said contact; al high speed valve constantly connected withv said cylinder, a medium speed valve, a low speed valve, all of which valves are biased .to the closed posi-,- tion, a high speed magnet, a medium speed magnet and a low speed magnet, means operating when said high speed magnet is energized to connect saidv cylinder with a source of Vfluid pressure through a restricted orifice, means operating When said medium speed magnet is energized and said high speed magnet is cle-energized to connect said cylinder with rsaid medium speed valve and with said source of fluid pressure and restricted orifice, means operating When said low speed magnet is energized and said high speed and medium speed magnets are de-energized to connect said cylinder With said low speed valve as Well as With said sourc of pressure and restricted orifice, means operating When all of said magnets are de.- energized to connect said cylinder with atmosphere but not with said source of pressure; and means for opening said low speed valve when the speed of the train exceeds al given 10W value, said medium ,speed valve When the speed exceeds a given medium value,`

and said high speed valve when the speed exceeds ay given high value, means for energizing said high speed magnet under clear traffic conditions and said medium. speed magnet under caution trafiic conditions, a normally open acknowledging. switch, means for energizing said lowspeed magnet if said switch is closed under danger trafhc conditions before said train governing mechanismis set into operation, and means for subsequently keeping said low speed magnetenergized as longas danger vconditions exist.

12. Train control apparatus comprising aV cylinder, a movable member associated with said cylinder and responsive to variations of pressure therein, a contact operated by said member, train governing mechanism controlled by said Contact; a high speed valve constantly connected With said cylinder, a medium speed valve, a loW speed valve, all of which valves are biased to the closed position, a high speed magnet, a medium speed magnet and a low speed magnet, a high speed pilot valve controlled by said high speed magnet and operating when the magnet is energized to connect said cylinder with a source of fluid pressure through a restricted orice, a Inedium speed pilot valve controlled by said medium speed magnet and operating when the magnet is energized and said high speed magnet is de-energized to connect said cylinder with said medium speed valve and With said source of fluid pressure and restricted orifice, a loW speed pilot valve controlled by said loW speed magnet and operating when the magnet is energized and the other two magnets are de-energized` to connect said cylinder ywith said loW speed valve as Well as with said iiuid pressuresource and restricted orifice, said pilot valvestoperating y,when all .three magnets are de-energized to connect said cylinder with atmosphere but not with said source of pressure, and means lfor open- -ing' said low=speed valve when the speed-of the train exceeds a given lowvalue, said me- 13. Train control apparatus comprising a cylinder, la movable member associated with said cylinderl and responsive to -variations of pressure therein, a contact operated by .said member, train governing mechanism controlled bysaid contact; a low speed magnet, a

normally closed low speed valve, means operating under tratiic conditions requiring low 'speed for connecting said cylinder with atmosphere it said magnet is de-energized but tor-connecting` said cylinder with said valve Yand also with a lsource of fluid pressure -through a restrictedv orifice if theI magnet is energized, means-for opening said valve when the speed or' the train exceedsa given low speed,VA ya normally open `acknowledging switch, means for energizing said magnet if said switchis closed under traiiic conditions requiring low speed before said train governing mechanism is set` into operation, and means for subsequently keepingsaid magnet energized as long as tratiic conditions requir- -ing low speed persist.,-

114. Train control 'apparatus comprising a cylinder, a movable member associated with said'cylinder and responsive to variations of pressure therein, a contact operated by said member, train governing mechanism Ycontrolled by said contact; a low speed magnet, a normally closed low speed valve, means'operating under traffic conditions requiring low speed for connecting said cylinder with atmosphere if said magnet is de-energized but for connecting said cylinder with said valve and also with a source of iiuid pressure through a restricted oriice if the magnet is energized, means for opening said valve when the speed. of the train exceeds a given low speed, va normallyV open acknowledging switch, a relay having a contact closed under conditions requiring low speed, acontact operated by said magnet and closed only when the magnet is energized, a pick-up circuit toi' said magnet including said switch and said 1 relay contact, and a holding circuit for said magnet including said relay contact and said magnet operated contact.

l5. Train control apparatus comprising a cylinder connected with a source of fluid pressure through a restricted oriiice a normally closed valve connected with said cylinder, a centrifugal device operatively connected with a wheel ofthe train, means operated by said centrifugal device for opening said valve when the speed ot the train exceeds a given value, a movable member responsive to 4variations of the pressure in said cylinder, `a contact operated lby said member, a second vrestricted orifice interposed between said cylinder and said valve to delay the operation Vofsaid contact in response to the opening ot the valve, a check valve connected around said second restricted orifice to permit quick chargingof said cylinder from said source when said first valve closes, and train govern-- ing mechanism controlled by said contact.

In testimony whereof I atix my signature.

LLOYD v. Lnwis'. 

